PARTY TALK

https://dictionaryblog.cambridge.org/2014/12/23/party-talk-the-language-of-party-chat/
by Kate Woodford​​​​

With the party season in full swing (= at its busiest now), we consider the language of socializing (= enjoying yourself with other people). We’re looking especially at words and phrases which are used to describe the different ways that people behave at a party and the sort of conversations that party guests may have.
Some people are very sociable (= liking meeting people). For them, a party is an opportunity to meet and chat to many people. They may choose to mingle, moving around the room and talking to a lot of guests: I guess I’d better go and mingle with my guests.
Other guests may be meeting for the first time. They may just exchange pleasantries, meaning that they say things to each other which are polite and pleasant but not especially interesting or important: Sarah introduced us at her party and we exchanged pleasantries. Another way of saying this is to make small talk: He doesn’t especially enjoy making small talk with people he doesn’t know. The informal noun chit-chat is also used to refer to conversation about matters that are not important: I don’t even remember what we spoke about – I think it was just the usual party chit-chat.
Some people like to keep the conversation light-hearted (= happy and not serious). They may enjoy a bit of banter in which they make jokes with people and laugh at them: There was the usual banter between the guys. ‘Banter’ is also a verb: He stood around bantering with his colleagues for a while.
Not all conversation is fun and jokey, however. Two close friends may use the opportunity to have a heart-to-heart, talking seriously about their feelings on subjects that are important to them: Paul and Helen seemed to be having a heart-to-heart so I didn’t like to disturb them.
Elsewhere at the same party, a guest may see old friend that they have not seen for a while and may catch up (= hear that person’s news): It was so nice to see you at Nicole’s party and catch up. This phrase is also used as a noun: Let’s meet in the New Year and have a proper catch-up then.
If two people meet for the first time and immediately get on (= enjoy each other’s company), they may be said to (informal) hit it off: I introduced Zoe to your brother and they really hit it off. You might also say that they get on like a house on fire : I wasn’t expecting them to have much in common but they got on like a house on fire.